Android selectableItemBackground的代码实现

Android xml文件中android:background="?attr/selectableItemBackground"代码实现为：

//5.0以上系统判断
if (Build.VERSION.SDK_INT >= 21) {
    int[] attrs = {android.R.attr.selectableItemBackground};
    TypedArray typedArray = context.getTheme().obtainStyledAttributes(attrs);
    int resourceId = typedArray.getResourceId(0, 0);
    textView.setBackgroundResource(resourceId);
}